Near-infrared spectroscopy with a fiber-optic probe for state variables determination in solid-state fermentation

This work studied the feasibility of near-infrared spectroscopy (NIRS) with a fiber-optic probe for the prediction of state variables in solid-state fermentation (SSF) samples with neither previous treatment nor manipulation. The models were developed using 50 samples and had the following root mean square error of cross-validation (RMSECV): 0.0253 for moisture content, 4.720 mg/g wet medium for biomass, 3.51 FPA/g wet medium for cellulase. Ten external samples were used to test the stability of the prediction models. The maximum absolute error and maximum relative error (%) were 0.0372 and 5.86 for moisture content, −6.51 and 11.63 for biomass, and 2.26 and 8.52 for cellulase. The predicted values using the NIRS technology were similar to the values obtained using chemical methods.